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0 J Repair procedures Cutting repair couplings (Cont.) On 2-inch couplings the center holes have been located near the middle of the coupling.Cut exactly between these two holes.The resulting half-couplings are 7 inches long.Two cuts are necessary when making 3-and 4-inch half-couplings. The resulting half-couplings are 51h inches long. D D 16 0 10 0 0 0 0 0 0 0 0 0 Fig.9-6.Cut full-length couplings so Cut to make 2-inch that all bolt holes on half-couplings half-couplings Cut to make 3- are equidistant from the ends. and 4-inch half-couplings 10 Primary system Recommended practices testing Plan tests carefully and carry them out with all due precautions.Pressurizing equipment should be suited to the size of the system and the pressure required and should be operated by qualified and experienced personnel only. r-----------------------------� 1 The following recommendations are offered only as a guide.Ameron assumes no 1 responsibility or liability for the consequences of any testing practices. L-----------------------------J �l Pressure sources should be capable of approaching test pressure gradually. • Use gauges with a full-scale reading of no more than twice the test pressure:Do not use a 100 psi gauge for a 10 psi test.Use reliable gauges calibrated against a dead weight tester and zeroed for atmospheric pressure. • Isolate tanks from the piping when pressure testing. • The recommended hydrostatic pressure is 150%of expected operating pressure and should be maintained at least 10 minutes. • Do not exceed 150%of system rating.Check the pressure rating of all the components of the system—not just the pipe—because hoses and flexible connectors are almost always rated lower than the pipe. • Do not adjust fittings while system is under pressure.If threaded adapters or bushings leak,release the pressure before attempting to tighten. • Temperature changes can affect the pressure in the test line.Substantial pressure increases may occur in closed systems exposed to the sun. Conversely,overnight decreases in pressure due to cooling from afternoon to early morning are normal and do not necessarily indicate a leak. • After testing,maintain 5 to 10 psi(35 to 70 kPa)in the system during subsequent construction so that damage caused by stakes,excavation equipment,etc.can be detected and corrected before pavement is installed or product is pumped. r-----------------------------� Ameron recommends hydrostatic testing of primary systems as the effects of I sudden pressure loss when testing with liquids are far less severe than with gases. I If pneumatic testing is necessary,restrain the system adequately to prevent I damage or injury in case of rapid pressure loss.Pneumatic testing can be extremely dangerous and is not recommended. I L-----------------------------J 15